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ffmpeg / libavcodec / cavsdec.c @ 5d2b15b8

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1
/*
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 * Chinese AVS video (AVS1-P2, JiZhun profile) decoder.
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 * Copyright (c) 2006  Stefan Gehrer <stefan.gehrer@gmx.de>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21

    
22
/**
23
 * @file cavs.c
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 * Chinese AVS video (AVS1-P2, JiZhun profile) decoder
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 * @author Stefan Gehrer <stefan.gehrer@gmx.de>
26
 */
27

    
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#include "avcodec.h"
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#include "bitstream.h"
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#include "golomb.h"
31
#include "cavs.h"
32

    
33
static const uint8_t mv_scan[4] = {
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    MV_FWD_X0,MV_FWD_X1,
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    MV_FWD_X2,MV_FWD_X3
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};
37

    
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static const uint8_t cbp_tab[64][2] = {
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  {63, 0},{15,15},{31,63},{47,31},{ 0,16},{14,32},{13,47},{11,13},
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  { 7,14},{ 5,11},{10,12},{ 8, 5},{12,10},{61, 7},{ 4,48},{55, 3},
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  { 1, 2},{ 2, 8},{59, 4},{ 3, 1},{62,61},{ 9,55},{ 6,59},{29,62},
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  {45,29},{51,27},{23,23},{39,19},{27,30},{46,28},{53, 9},{30, 6},
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  {43,60},{37,21},{60,44},{16,26},{21,51},{28,35},{19,18},{35,20},
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  {42,24},{26,53},{44,17},{32,37},{58,39},{24,45},{20,58},{17,43},
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  {18,42},{48,46},{22,36},{33,33},{25,34},{49,40},{40,52},{36,49},
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  {34,50},{50,56},{52,25},{54,22},{41,54},{56,57},{38,41},{57,38}
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};
48

    
49
/*****************************************************************************
50
 *
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 * motion vector prediction
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 *
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 ****************************************************************************/
54

    
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static inline void store_mvs(AVSContext *h) {
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    h->col_mv[(h->mby*h->mb_width + h->mbx)*4 + 0] = h->mv[MV_FWD_X0];
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    h->col_mv[(h->mby*h->mb_width + h->mbx)*4 + 1] = h->mv[MV_FWD_X1];
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    h->col_mv[(h->mby*h->mb_width + h->mbx)*4 + 2] = h->mv[MV_FWD_X2];
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    h->col_mv[(h->mby*h->mb_width + h->mbx)*4 + 3] = h->mv[MV_FWD_X3];
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}
61

    
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static inline void mv_pred_direct(AVSContext *h, vector_t *pmv_fw,
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                                  vector_t *col_mv) {
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    vector_t *pmv_bw = pmv_fw + MV_BWD_OFFS;
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    int den = h->direct_den[col_mv->ref];
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    int m = col_mv->x >> 31;
67

    
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    pmv_fw->dist = h->dist[1];
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    pmv_bw->dist = h->dist[0];
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    pmv_fw->ref = 1;
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    pmv_bw->ref = 0;
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    /* scale the co-located motion vector according to its temporal span */
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    pmv_fw->x = (((den+(den*col_mv->x*pmv_fw->dist^m)-m-1)>>14)^m)-m;
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    pmv_bw->x = m-(((den+(den*col_mv->x*pmv_bw->dist^m)-m-1)>>14)^m);
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    m = col_mv->y >> 31;
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    pmv_fw->y = (((den+(den*col_mv->y*pmv_fw->dist^m)-m-1)>>14)^m)-m;
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    pmv_bw->y = m-(((den+(den*col_mv->y*pmv_bw->dist^m)-m-1)>>14)^m);
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}
79

    
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static inline void mv_pred_sym(AVSContext *h, vector_t *src, enum block_t size) {
81
    vector_t *dst = src + MV_BWD_OFFS;
82

    
83
    /* backward mv is the scaled and negated forward mv */
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    dst->x = -((src->x * h->sym_factor + 256) >> 9);
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    dst->y = -((src->y * h->sym_factor + 256) >> 9);
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    dst->ref = 0;
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    dst->dist = h->dist[0];
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    set_mvs(dst, size);
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}
90

    
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/*****************************************************************************
92
 *
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 * residual data decoding
94
 *
95
 ****************************************************************************/
96

    
97
/** kth-order exponential golomb code */
98
static inline int get_ue_code(GetBitContext *gb, int order) {
99
    if(order) {
100
        int ret = get_ue_golomb(gb) << order;
101
        return ret + get_bits(gb,order);
102
    }
103
    return get_ue_golomb(gb);
104
}
105

    
106
/**
107
 * decode coefficients from one 8x8 block, dequantize, inverse transform
108
 *  and add them to sample block
109
 * @param r pointer to 2D VLC table
110
 * @param esc_golomb_order escape codes are k-golomb with this order k
111
 * @param qp quantizer
112
 * @param dst location of sample block
113
 * @param stride line stride in frame buffer
114
 */
115
static int decode_residual_block(AVSContext *h, GetBitContext *gb,
116
                                 const dec_2dvlc_t *r, int esc_golomb_order,
117
                                 int qp, uint8_t *dst, int stride) {
118
    int i, level_code, esc_code, level, run, mask;
119
    DCTELEM level_buf[64];
120
    uint8_t run_buf[64];
121
    DCTELEM *block = h->block;
122

    
123
    for(i=0;i<65;i++) {
124
        level_code = get_ue_code(gb,r->golomb_order);
125
        if(level_code >= ESCAPE_CODE) {
126
            run = ((level_code - ESCAPE_CODE) >> 1) + 1;
127
            esc_code = get_ue_code(gb,esc_golomb_order);
128
            level = esc_code + (run > r->max_run ? 1 : r->level_add[run]);
129
            while(level > r->inc_limit)
130
                r++;
131
            mask = -(level_code & 1);
132
            level = (level^mask) - mask;
133
        } else {
134
            level = r->rltab[level_code][0];
135
            if(!level) //end of block signal
136
                break;
137
            run   = r->rltab[level_code][1];
138
            r += r->rltab[level_code][2];
139
        }
140
        level_buf[i] = level;
141
        run_buf[i] = run;
142
    }
143
    if(dequant(h,level_buf, run_buf, block, ff_cavs_dequant_mul[qp],
144
               ff_cavs_dequant_shift[qp], i))
145
        return -1;
146
    h->s.dsp.cavs_idct8_add(dst,block,stride);
147
    return 0;
148
}
149

    
150

    
151
static inline void decode_residual_chroma(AVSContext *h) {
152
    if(h->cbp & (1<<4))
153
        decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
154
                              ff_cavs_chroma_qp[h->qp],h->cu,h->c_stride);
155
    if(h->cbp & (1<<5))
156
        decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
157
                              ff_cavs_chroma_qp[h->qp],h->cv,h->c_stride);
158
}
159

    
160
static inline int decode_residual_inter(AVSContext *h) {
161
    int block;
162

    
163
    /* get coded block pattern */
164
    int cbp= get_ue_golomb(&h->s.gb);
165
    if(cbp > 63){
166
        av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n");
167
        return -1;
168
    }
169
    h->cbp = cbp_tab[cbp][1];
170

    
171
    /* get quantizer */
172
    if(h->cbp && !h->qp_fixed)
173
        h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63;
174
    for(block=0;block<4;block++)
175
        if(h->cbp & (1<<block))
176
            decode_residual_block(h,&h->s.gb,ff_cavs_inter_dec,0,h->qp,
177
                                  h->cy + h->luma_scan[block], h->l_stride);
178
    decode_residual_chroma(h);
179

    
180
    return 0;
181
}
182

    
183
/*****************************************************************************
184
 *
185
 * macroblock level
186
 *
187
 ****************************************************************************/
188

    
189
static int decode_mb_i(AVSContext *h, int cbp_code) {
190
    GetBitContext *gb = &h->s.gb;
191
    int block, pred_mode_uv;
192
    uint8_t top[18];
193
    uint8_t *left = NULL;
194
    uint8_t *d;
195

    
196
    ff_cavs_init_mb(h);
197

    
198
    /* get intra prediction modes from stream */
199
    for(block=0;block<4;block++) {
200
        int nA,nB,predpred;
201
        int pos = ff_cavs_scan3x3[block];
202

    
203
        nA = h->pred_mode_Y[pos-1];
204
        nB = h->pred_mode_Y[pos-3];
205
        predpred = FFMIN(nA,nB);
206
        if(predpred == NOT_AVAIL) // if either is not available
207
            predpred = INTRA_L_LP;
208
        if(!get_bits1(gb)){
209
            int rem_mode= get_bits(gb, 2);
210
            predpred = rem_mode + (rem_mode >= predpred);
211
        }
212
        h->pred_mode_Y[pos] = predpred;
213
    }
214
    pred_mode_uv = get_ue_golomb(gb);
215
    if(pred_mode_uv > 6) {
216
        av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n");
217
        return -1;
218
    }
219
    ff_cavs_modify_mb_i(h, &pred_mode_uv);
220

    
221
    /* get coded block pattern */
222
    if(h->pic_type == FF_I_TYPE)
223
        cbp_code = get_ue_golomb(gb);
224
    if(cbp_code > 63){
225
        av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n");
226
        return -1;
227
    }
228
    h->cbp = cbp_tab[cbp_code][0];
229
    if(h->cbp && !h->qp_fixed)
230
        h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta
231

    
232
    /* luma intra prediction interleaved with residual decode/transform/add */
233
    for(block=0;block<4;block++) {
234
        d = h->cy + h->luma_scan[block];
235
        ff_cavs_load_intra_pred_luma(h, top, &left, block);
236
        h->intra_pred_l[h->pred_mode_Y[ff_cavs_scan3x3[block]]]
237
            (d, top, left, h->l_stride);
238
        if(h->cbp & (1<<block))
239
            decode_residual_block(h,gb,ff_cavs_intra_dec,1,h->qp,d,h->l_stride);
240
    }
241

    
242
    /* chroma intra prediction */
243
    ff_cavs_load_intra_pred_chroma(h);
244
    h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx*10],
245
                                  h->left_border_u, h->c_stride);
246
    h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx*10],
247
                                  h->left_border_v, h->c_stride);
248

    
249
    decode_residual_chroma(h);
250
    ff_cavs_filter(h,I_8X8);
251
    set_mv_intra(h);
252
    return 0;
253
}
254

    
255
static void decode_mb_p(AVSContext *h, enum mb_t mb_type) {
256
    GetBitContext *gb = &h->s.gb;
257
    int ref[4];
258

    
259
    ff_cavs_init_mb(h);
260
    switch(mb_type) {
261
    case P_SKIP:
262
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP,  BLK_16X16, 0);
263
        break;
264
    case P_16X16:
265
        ref[0] = h->ref_flag ? 0 : get_bits1(gb);
266
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16,ref[0]);
267
        break;
268
    case P_16X8:
269
        ref[0] = h->ref_flag ? 0 : get_bits1(gb);
270
        ref[2] = h->ref_flag ? 0 : get_bits1(gb);
271
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP,    BLK_16X8, ref[0]);
272
        ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT,   BLK_16X8, ref[2]);
273
        break;
274
    case P_8X16:
275
        ref[0] = h->ref_flag ? 0 : get_bits1(gb);
276
        ref[1] = h->ref_flag ? 0 : get_bits1(gb);
277
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT,   BLK_8X16, ref[0]);
278
        ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT,BLK_8X16, ref[1]);
279
        break;
280
    case P_8X8:
281
        ref[0] = h->ref_flag ? 0 : get_bits1(gb);
282
        ref[1] = h->ref_flag ? 0 : get_bits1(gb);
283
        ref[2] = h->ref_flag ? 0 : get_bits1(gb);
284
        ref[3] = h->ref_flag ? 0 : get_bits1(gb);
285
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN,   BLK_8X8, ref[0]);
286
        ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN,   BLK_8X8, ref[1]);
287
        ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN,   BLK_8X8, ref[2]);
288
        ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN,   BLK_8X8, ref[3]);
289
    }
290
    ff_cavs_inter(h, mb_type);
291
    set_intra_mode_default(h);
292
    store_mvs(h);
293
    if(mb_type != P_SKIP)
294
        decode_residual_inter(h);
295
    ff_cavs_filter(h,mb_type);
296
    *h->col_type = mb_type;
297
}
298

    
299
static void decode_mb_b(AVSContext *h, enum mb_t mb_type) {
300
    int block;
301
    enum sub_mb_t sub_type[4];
302
    int flags;
303

    
304
    ff_cavs_init_mb(h);
305

    
306
    /* reset all MVs */
307
    h->mv[MV_FWD_X0] = ff_cavs_dir_mv;
308
    set_mvs(&h->mv[MV_FWD_X0], BLK_16X16);
309
    h->mv[MV_BWD_X0] = ff_cavs_dir_mv;
310
    set_mvs(&h->mv[MV_BWD_X0], BLK_16X16);
311
    switch(mb_type) {
312
    case B_SKIP:
313
    case B_DIRECT:
314
        if(!(*h->col_type)) {
315
            /* intra MB at co-location, do in-plane prediction */
316
            ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1);
317
            ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0);
318
        } else
319
            /* direct prediction from co-located P MB, block-wise */
320
            for(block=0;block<4;block++)
321
                mv_pred_direct(h,&h->mv[mv_scan[block]],
322
                            &h->col_mv[(h->mby*h->mb_width+h->mbx)*4 + block]);
323
        break;
324
    case B_FWD_16X16:
325
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
326
        break;
327
    case B_SYM_16X16:
328
        ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
329
        mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16);
330
        break;
331
    case B_BWD_16X16:
332
        ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0);
333
        break;
334
    case B_8X8:
335
        for(block=0;block<4;block++)
336
            sub_type[block] = get_bits(&h->s.gb,2);
337
        for(block=0;block<4;block++) {
338
            switch(sub_type[block]) {
339
            case B_SUB_DIRECT:
340
                if(!(*h->col_type)) {
341
                    /* intra MB at co-location, do in-plane prediction */
342
                    ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
343
                            MV_PRED_BSKIP, BLK_8X8, 1);
344
                    ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
345
                            mv_scan[block]-3+MV_BWD_OFFS,
346
                            MV_PRED_BSKIP, BLK_8X8, 0);
347
                } else
348
                    mv_pred_direct(h,&h->mv[mv_scan[block]],
349
                                   &h->col_mv[(h->mby*h->mb_width + h->mbx)*4 + block]);
350
                break;
351
            case B_SUB_FWD:
352
                ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
353
                        MV_PRED_MEDIAN, BLK_8X8, 1);
354
                break;
355
            case B_SUB_SYM:
356
                ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
357
                        MV_PRED_MEDIAN, BLK_8X8, 1);
358
                mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8);
359
                break;
360
            }
361
        }
362
        for(block=0;block<4;block++) {
363
            if(sub_type[block] == B_SUB_BWD)
364
                ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
365
                        mv_scan[block]+MV_BWD_OFFS-3,
366
                        MV_PRED_MEDIAN, BLK_8X8, 0);
367
        }
368
        break;
369
    default:
370
        assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8));
371
        flags = ff_cavs_partition_flags[mb_type];
372
        if(mb_type & 1) { /* 16x8 macroblock types */
373
            if(flags & FWD0)
374
                ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP,  BLK_16X8, 1);
375
            if(flags & SYM0)
376
                mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8);
377
            if(flags & FWD1)
378
                ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1);
379
            if(flags & SYM1)
380
                mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8);
381
            if(flags & BWD0)
382
                ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP,  BLK_16X8, 0);
383
            if(flags & BWD1)
384
                ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0);
385
        } else {          /* 8x16 macroblock types */
386
            if(flags & FWD0)
387
                ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1);
388
            if(flags & SYM0)
389
                mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16);
390
            if(flags & FWD1)
391
                ff_cavs_mv(h,MV_FWD_X1,MV_FWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,1);
392
            if(flags & SYM1)
393
                mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16);
394
            if(flags & BWD0)
395
                ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0);
396
            if(flags & BWD1)
397
                ff_cavs_mv(h,MV_BWD_X1,MV_BWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,0);
398
        }
399
    }
400
    ff_cavs_inter(h, mb_type);
401
    set_intra_mode_default(h);
402
    if(mb_type != B_SKIP)
403
        decode_residual_inter(h);
404
    ff_cavs_filter(h,mb_type);
405
}
406

    
407
/*****************************************************************************
408
 *
409
 * slice level
410
 *
411
 ****************************************************************************/
412

    
413
static inline int decode_slice_header(AVSContext *h, GetBitContext *gb) {
414
    if(h->stc > 0xAF)
415
        av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc);
416
    h->mby = h->stc;
417
    if((h->mby == 0) && (!h->qp_fixed)){
418
        h->qp_fixed = get_bits1(gb);
419
        h->qp = get_bits(gb,6);
420
    }
421
    /* inter frame or second slice can have weighting params */
422
    if((h->pic_type != FF_I_TYPE) || (!h->pic_structure && h->mby >= h->mb_width/2))
423
        if(get_bits1(gb)) { //slice_weighting_flag
424
            av_log(h->s.avctx, AV_LOG_ERROR,
425
                   "weighted prediction not yet supported\n");
426
        }
427
    return 0;
428
}
429

    
430
static inline void check_for_slice(AVSContext *h) {
431
    GetBitContext *gb = &h->s.gb;
432
    int align;
433
    align = (-get_bits_count(gb)) & 7;
434
    if((show_bits_long(gb,24+align) & 0xFFFFFF) == 0x000001) {
435
        get_bits_long(gb,24+align);
436
        h->stc = get_bits(gb,8);
437
        decode_slice_header(h,gb);
438
    }
439
}
440

    
441
/*****************************************************************************
442
 *
443
 * frame level
444
 *
445
 ****************************************************************************/
446

    
447
static int decode_pic(AVSContext *h) {
448
    MpegEncContext *s = &h->s;
449
    int skip_count;
450
    enum mb_t mb_type;
451

    
452
    if (!s->context_initialized) {
453
        s->avctx->idct_algo = FF_IDCT_CAVS;
454
        if (MPV_common_init(s) < 0)
455
            return -1;
456
        ff_init_scantable(s->dsp.idct_permutation,&h->scantable,ff_zigzag_direct);
457
    }
458
    get_bits(&s->gb,16);//bbv_dwlay
459
    if(h->stc == PIC_PB_START_CODE) {
460
        h->pic_type = get_bits(&s->gb,2) + FF_I_TYPE;
461
        if(h->pic_type > FF_B_TYPE) {
462
            av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n");
463
            return -1;
464
        }
465
        /* make sure we have the reference frames we need */
466
        if(!h->DPB[0].data[0] ||
467
          (!h->DPB[1].data[0] && h->pic_type == FF_B_TYPE))
468
            return -1;
469
    } else {
470
        h->pic_type = FF_I_TYPE;
471
        if(get_bits1(&s->gb))
472
            get_bits(&s->gb,16);//time_code
473
    }
474
    /* release last B frame */
475
    if(h->picture.data[0])
476
        s->avctx->release_buffer(s->avctx, (AVFrame *)&h->picture);
477

    
478
    s->avctx->get_buffer(s->avctx, (AVFrame *)&h->picture);
479
    ff_cavs_init_pic(h);
480
    h->picture.poc = get_bits(&s->gb,8)*2;
481

    
482
    /* get temporal distances and MV scaling factors */
483
    if(h->pic_type != FF_B_TYPE) {
484
        h->dist[0] = (h->picture.poc - h->DPB[0].poc  + 512) % 512;
485
    } else {
486
        h->dist[0] = (h->DPB[0].poc  - h->picture.poc + 512) % 512;
487
    }
488
    h->dist[1] = (h->picture.poc - h->DPB[1].poc  + 512) % 512;
489
    h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0;
490
    h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0;
491
    if(h->pic_type == FF_B_TYPE) {
492
        h->sym_factor = h->dist[0]*h->scale_den[1];
493
    } else {
494
        h->direct_den[0] = h->dist[0] ? 16384/h->dist[0] : 0;
495
        h->direct_den[1] = h->dist[1] ? 16384/h->dist[1] : 0;
496
    }
497

    
498
    if(s->low_delay)
499
        get_ue_golomb(&s->gb); //bbv_check_times
500
    h->progressive             = get_bits1(&s->gb);
501
    if(h->progressive)
502
        h->pic_structure = 1;
503
    else if(!(h->pic_structure = get_bits1(&s->gb) && (h->stc == PIC_PB_START_CODE)) )
504
        get_bits1(&s->gb);     //advanced_pred_mode_disable
505
    skip_bits1(&s->gb);        //top_field_first
506
    skip_bits1(&s->gb);        //repeat_first_field
507
    h->qp_fixed                = get_bits1(&s->gb);
508
    h->qp                      = get_bits(&s->gb,6);
509
    if(h->pic_type == FF_I_TYPE) {
510
        if(!h->progressive && !h->pic_structure)
511
            skip_bits1(&s->gb);//what is this?
512
        skip_bits(&s->gb,4);   //reserved bits
513
    } else {
514
        if(!(h->pic_type == FF_B_TYPE && h->pic_structure == 1))
515
            h->ref_flag        = get_bits1(&s->gb);
516
        skip_bits(&s->gb,4);   //reserved bits
517
        h->skip_mode_flag      = get_bits1(&s->gb);
518
    }
519
    h->loop_filter_disable     = get_bits1(&s->gb);
520
    if(!h->loop_filter_disable && get_bits1(&s->gb)) {
521
        h->alpha_offset        = get_se_golomb(&s->gb);
522
        h->beta_offset         = get_se_golomb(&s->gb);
523
    } else {
524
        h->alpha_offset = h->beta_offset  = 0;
525
    }
526
    check_for_slice(h);
527
    if(h->pic_type == FF_I_TYPE) {
528
        do {
529
            decode_mb_i(h, 0);
530
        } while(ff_cavs_next_mb(h));
531
    } else if(h->pic_type == FF_P_TYPE) {
532
        do {
533
            if(h->skip_mode_flag) {
534
                skip_count = get_ue_golomb(&s->gb);
535
                while(skip_count--) {
536
                    decode_mb_p(h,P_SKIP);
537
                    if(!ff_cavs_next_mb(h))
538
                        goto done;
539
                }
540
                mb_type = get_ue_golomb(&s->gb) + P_16X16;
541
            } else
542
                mb_type = get_ue_golomb(&s->gb) + P_SKIP;
543
            if(mb_type > P_8X8) {
544
                decode_mb_i(h, mb_type - P_8X8 - 1);
545
            } else
546
                decode_mb_p(h,mb_type);
547
        } while(ff_cavs_next_mb(h));
548
    } else { /* FF_B_TYPE */
549
        do {
550
            if(h->skip_mode_flag) {
551
                skip_count = get_ue_golomb(&s->gb);
552
                while(skip_count--) {
553
                    decode_mb_b(h,B_SKIP);
554
                    if(!ff_cavs_next_mb(h))
555
                        goto done;
556
                }
557
                mb_type = get_ue_golomb(&s->gb) + B_DIRECT;
558
            } else
559
                mb_type = get_ue_golomb(&s->gb) + B_SKIP;
560
            if(mb_type > B_8X8) {
561
                decode_mb_i(h, mb_type - B_8X8 - 1);
562
            } else
563
                decode_mb_b(h,mb_type);
564
        } while(ff_cavs_next_mb(h));
565
    }
566
 done:
567
    if(h->pic_type != FF_B_TYPE) {
568
        if(h->DPB[1].data[0])
569
            s->avctx->release_buffer(s->avctx, (AVFrame *)&h->DPB[1]);
570
        memcpy(&h->DPB[1], &h->DPB[0], sizeof(Picture));
571
        memcpy(&h->DPB[0], &h->picture, sizeof(Picture));
572
        memset(&h->picture,0,sizeof(Picture));
573
    }
574
    return 0;
575
}
576

    
577
/*****************************************************************************
578
 *
579
 * headers and interface
580
 *
581
 ****************************************************************************/
582

    
583
static int decode_seq_header(AVSContext *h) {
584
    MpegEncContext *s = &h->s;
585
    int frame_rate_code;
586

    
587
    h->profile =         get_bits(&s->gb,8);
588
    h->level =           get_bits(&s->gb,8);
589
    skip_bits1(&s->gb); //progressive sequence
590
    s->width =           get_bits(&s->gb,14);
591
    s->height =          get_bits(&s->gb,14);
592
    skip_bits(&s->gb,2); //chroma format
593
    skip_bits(&s->gb,3); //sample_precision
594
    h->aspect_ratio =    get_bits(&s->gb,4);
595
    frame_rate_code =    get_bits(&s->gb,4);
596
    skip_bits(&s->gb,18);//bit_rate_lower
597
    skip_bits1(&s->gb);  //marker_bit
598
    skip_bits(&s->gb,12);//bit_rate_upper
599
    s->low_delay =       get_bits1(&s->gb);
600
    h->mb_width  = (s->width  + 15) >> 4;
601
    h->mb_height = (s->height + 15) >> 4;
602
    h->s.avctx->time_base.den = ff_frame_rate_tab[frame_rate_code].num;
603
    h->s.avctx->time_base.num = ff_frame_rate_tab[frame_rate_code].den;
604
    h->s.avctx->width  = s->width;
605
    h->s.avctx->height = s->height;
606
    if(!h->top_qp)
607
        ff_cavs_init_top_lines(h);
608
    return 0;
609
}
610

    
611
static void cavs_flush(AVCodecContext * avctx) {
612
    AVSContext *h = avctx->priv_data;
613
    h->got_keyframe = 0;
614
}
615

    
616
static int cavs_decode_frame(AVCodecContext * avctx,void *data, int *data_size,
617
                             uint8_t * buf, int buf_size) {
618
    AVSContext *h = avctx->priv_data;
619
    MpegEncContext *s = &h->s;
620
    int input_size;
621
    const uint8_t *buf_end;
622
    const uint8_t *buf_ptr;
623
    AVFrame *picture = data;
624
    uint32_t stc;
625

    
626
    s->avctx = avctx;
627

    
628
    if (buf_size == 0) {
629
        if(!s->low_delay && h->DPB[0].data[0]) {
630
            *data_size = sizeof(AVPicture);
631
            *picture = *(AVFrame *) &h->DPB[0];
632
        }
633
        return 0;
634
    }
635

    
636
    buf_ptr = buf;
637
    buf_end = buf + buf_size;
638
    for(;;) {
639
        buf_ptr = ff_find_start_code(buf_ptr,buf_end, &stc);
640
        if(stc & 0xFFFFFE00)
641
            return FFMAX(0, buf_ptr - buf - s->parse_context.last_index);
642
        input_size = (buf_end - buf_ptr)*8;
643
        switch(stc) {
644
        case CAVS_START_CODE:
645
            init_get_bits(&s->gb, buf_ptr, input_size);
646
            decode_seq_header(h);
647
            break;
648
        case PIC_I_START_CODE:
649
            if(!h->got_keyframe) {
650
                if(h->DPB[0].data[0])
651
                    avctx->release_buffer(avctx, (AVFrame *)&h->DPB[0]);
652
                if(h->DPB[1].data[0])
653
                    avctx->release_buffer(avctx, (AVFrame *)&h->DPB[1]);
654
                h->got_keyframe = 1;
655
            }
656
        case PIC_PB_START_CODE:
657
            *data_size = 0;
658
            if(!h->got_keyframe)
659
                break;
660
            init_get_bits(&s->gb, buf_ptr, input_size);
661
            h->stc = stc;
662
            if(decode_pic(h))
663
                break;
664
            *data_size = sizeof(AVPicture);
665
            if(h->pic_type != FF_B_TYPE) {
666
                if(h->DPB[1].data[0]) {
667
                    *picture = *(AVFrame *) &h->DPB[1];
668
                } else {
669
                    *data_size = 0;
670
                }
671
            } else
672
                *picture = *(AVFrame *) &h->picture;
673
            break;
674
        case EXT_START_CODE:
675
            //mpeg_decode_extension(avctx,buf_ptr, input_size);
676
            break;
677
        case USER_START_CODE:
678
            //mpeg_decode_user_data(avctx,buf_ptr, input_size);
679
            break;
680
        default:
681
            if (stc >= SLICE_MIN_START_CODE &&
682
                stc <= SLICE_MAX_START_CODE) {
683
                init_get_bits(&s->gb, buf_ptr, input_size);
684
                decode_slice_header(h, &s->gb);
685
            }
686
            break;
687
        }
688
    }
689
}
690

    
691
AVCodec cavs_decoder = {
692
    "cavs",
693
    CODEC_TYPE_VIDEO,
694
    CODEC_ID_CAVS,
695
    sizeof(AVSContext),
696
    ff_cavs_init,
697
    NULL,
698
    ff_cavs_end,
699
    cavs_decode_frame,
700
    CODEC_CAP_DR1 | CODEC_CAP_DELAY,
701
    .flush= cavs_flush,
702
};